Move arm from ports to libc.

I've moved the ARM port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply

git mv ports/sysdeps/arm sysdeps/arm
git mv ports/sysdeps/unix/arm sysdeps/unix/arm
git mv ports/sysdeps/unix/sysv/linux/arm sysdeps/unix/sysv/linux/arm

and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.arm similar to that at the top of
ChangeLog.powerpc.  There is deliberately no NEWS change, as I think
it makes the most sense to put in a general note above all ports
having moved if we can achieve that for 2.20.

Tested that disassembly of installed shared libraries for arm is the
same before and after this patch, except for data (not instructions)
in ld.so (there are assertions in sysdeps/arm/dl-machine.h, and the
path by which that file is found, and so by which it appears in the
assertion message, changes as a result of the move).

	* sysdeps/arm: Move directory from ports/sysdeps/arm.
	* sysdeps/unix/arm: Move directory from ports/sysdeps/unix/arm.
	* sysdeps/unix/sysv/linux/arm: Move directory from
	ports/sysdeps/unix/sysv/linux/arm.
	* README: Update listing for arm-*-linux-gnueabi.

ports/ChangeLog.arm:
	* sysdeps/arm: Move directory to ../sysdeps/arm.
	* sysdeps/unix/arm: Move directory to ../sysdeps.arm.
	* sysdeps/unix/sysv/linux/arm: Move directory to
	../sysdeps/unix/sysv/linux/arm.

1 files changed, 104 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/arm/setcontext.S b/sysdeps/unix/sysv/linux/arm/setcontext.S
new file mode 100644
index 0000000000..7b9b511b80
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/setcontext.S
@@ -0,0 +1,104 @@
+/* Copyright (C) 2012-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* ??? Needs more rearrangement for the LDM to handle thumb mode.  */
+#define NO_THUMB
+#include <sysdep.h>
+#include <rtld-global-offsets.h>
+
+#include "ucontext_i.h"
+
+	.syntax unified
+	.text
+
+/* int setcontext (const ucontext_t *ucp) */
+
+ENTRY(__setcontext)
+	mov	r4, r0
+	add	r0, r0, #UCONTEXT_REGSPACE
+
+	/* Restore the VFP registers.  Copied from arm/__longjmp.S.  */
+#ifdef PIC
+	ldr     r2, 1f
+	ldr     r1, .Lrtld_global_ro
+0:      add     r2, pc, r2
+	ldr     r2, [r2, r1]
+	ldr     r2, [r2, #RTLD_GLOBAL_RO_DL_HWCAP_OFFSET]
+#else
+	ldr     r2, .Lhwcap
+	ldr     r2, [r2, #0]
+#endif
+
+#ifdef __SOFTFP__
+	tst     r2, #HWCAP_ARM_VFP
+	beq     .Lno_vfp_sc
+#endif
+
+	/* Following instruction is vldmia r0!, {d8-d15}.  */
+	ldc     p11, cr8, [r0], #64
+	/* Restore the floating-point status register.  */
+	ldr     r1, [r0], #4
+	/* Following instruction is fmxr fpscr, r1.  */
+	mcr     p10, 7, r1, cr1, cr0, 0
+.Lno_vfp_sc:
+	tst     r2, #HWCAP_ARM_IWMMXT
+	beq     .Lno_iwmmxt_sc
+
+	/* Restore the call-preserved iWMMXt registers.  */
+	/* Following instructions are wldrd wr10, [r0], #8 (etc.)  */
+	ldcl    p1, cr10, [r0], #8
+	ldcl    p1, cr11, [r0], #8
+	ldcl    p1, cr12, [r0], #8
+	ldcl    p1, cr13, [r0], #8
+	ldcl    p1, cr14, [r0], #8
+	ldcl    p1, cr15, [r0], #8
+.Lno_iwmmxt_sc:
+
+	/* Now bring back the signal status.  */
+	mov	r0, #SIG_SETMASK
+	add	r1, r4, #UCONTEXT_SIGMASK
+	mov	r2, #0
+	bl	PLTJMP(__sigprocmask)
+
+	/* Loading r0-r3 makes makecontext easier.  */
+	add     r14, r4, #MCONTEXT_ARM_R0
+	ldmia   r14, {r0-r12}
+	ldr     r13, [r14, #(MCONTEXT_ARM_SP - MCONTEXT_ARM_R0)]
+	add     r14, r14, #(MCONTEXT_ARM_LR - MCONTEXT_ARM_R0)
+	ldmia   r14, {r14, pc}
+
+END(setcontext)
+weak_alias(__setcontext, setcontext)
+
+	/* Called when a makecontext() context returns.  Start the
+	   context in R4 or fall through to exit().  */
+ENTRY(__startcontext)
+	movs    r0, r4
+	bne     PLTJMP(__setcontext)
+
+	@ New context was 0 - exit
+	b       PLTJMP(HIDDEN_JUMPTARGET(_exit))
+END(__startcontext)
+
+#ifdef PIC
+1:      .long   _GLOBAL_OFFSET_TABLE_ - 0b - PC_OFS
+.Lrtld_global_ro:
+	.long   C_SYMBOL_NAME(_rtld_global_ro)(GOT)
+#else
+.Lhwcap:
+	.long   C_SYMBOL_NAME(_dl_hwcap)
+#endif